<template>
  <view>
    <view class="scroll-view-container">
      <!-- 左侧的滚动视图区域 -->
      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh + 'px'}">
        <!-- <view class="left-scroll-view-item active">xxx</view> -->
        <view :class="['left-scroll-view-item',i===active?'active':'']" v-for="(item,i) in cateList" :key="i" 
        @click="activeChanged(i)">{{item.cat_name}}</view>
      </scroll-view>
      <!-- 右侧的滚动视图区域 -->
      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh + 'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, i2) in cateList2" :key="i2">
          <view class="cate-lv2-title">/ {{item2.cat_name}} /</view>
          <!-- 动态渲染三级分类的列表数据 -->
          <view class="cate-lv3-list">
            <!-- 三级分类 Item 项 -->
            <view class="cate-lv3-item" v-for="(item3, i3) in item2.children" :key="i3">
              <!-- 图片 -->
              <image :src="item3.cat_icon.replace('api-ugo-dev.itheima.net','api-hmugo-web.itheima.net')" mode="widthFix"/>
              <!-- 文本 -->
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
    </view>
  </view>
</template>
<script>
  export default {
    data() {
      return {
        // 窗口高度
        wh: 0,
        // 分类数据列表
        // 左边的
        cateList: [],
        // 右边的
        cateList2: [],
        active:0,
         // 滚动条距离顶部的距离
        scrollTop: 0
      };
    },
    onLoad(){
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight,
      this.getCateList()
      
    },
    methods:{
      async getCateList(){
        const { data: res } = await uni.$http.get('/api/public/v1/categories')
        if (res.meta.status !== 200) return uni.$showMsg()
        // 存数据
        this.cateList = res.message
        console.log(res)
        // 为二级分类赋值，刚开始先获取第一个的值
        this.cateList2 = res.message[0].children
      },
      activeChanged(i){
        this.active = i
        // 为二级分类列表重新赋值
        this.cateList2 = this.cateList[i].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      gotoGoodsList(item3){
        uni.navigateTo({
          url: '/subpkg/goods_list/goods_list?cid=' + item3.cat_id
        })
      }
    }
  }
</script>

<style lang="scss">
.scroll-view-container {
  display: flex;

  .left-scroll-view {
    width: 120px;

    .left-scroll-view-item {
      line-height: 60px;
      background-color: #f7f7f7;
      text-align: center;
      font-size: 12px;

      // 激活项的样式
      &.active {
        background-color: #ffffff;
        position: relative;

        // 渲染激活项左侧的红色指示边线
        &::before {
          content: ' ';
          display: block;
          width: 3px;
          height: 30px;
          background-color: #c00000;
          position: absolute;
          left: 0;
          top: 50%;
          transform: translateY(-50%);
        }
      }
    }
  }
}
.cate-lv2-title {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 15px 0;
}
.cate-lv3-list {
  display: flex;
  flex-wrap: wrap;

  .cate-lv3-item {
    width: 33.33%;
    margin-bottom: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;

    image {
      width: 60px;
      height: 60px;
    }

    text {
      font-size: 12px;
    }
  }
}
</style>
